In recent years, with increased capacities of magnetic disk drives, much effort has been made to increase the track density thereof. The increased track density has required more and more accurate head positioning. The accurate head positioning in turn requires improvement of rapid responsiveness in head positioning control, that is, an increase in control bandwidth. Thus, recently, a magnetic disk drive has been proposed which comprises a microactuator excellent in following high frequencies, in addition to a voice coil motor (VCM) actuator, that is, a magnetic disk drive with a dual stage actuator (DSA) structure applied thereto.
The microactuator is driven by applying a voltage to an element (for example, a piezoelectric element) forming the microactuator. The microactuator is displaced differently depending on whether a voltage is applied to the microactuator in a direction in which the voltage increases or in a direction in which the voltage decreases. That is, the microactuator has a hysteresis property for the applied voltage.
The hysteresis property of the microactuator may affect a seek operation for moving a head to a target track using both the VCM actuator and microactuator.